Species

myelin sheath

Summary

Summary: The lipid-rich sheath surrounding AXONS in both the central and peripheral nervous systems. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.

Top Publications

Biology of oligodendrocyte and myelin in the mammalian central nervous system

..The mechanisms of remyelination therefore provide critical clues for regeneration biologists that help them to determine why remyelination fails in MS and in other demyelinating diseases and how it might be enhanced therapeutically...

..and mouse genetics have provided insight into axon-glia signalling and the molecular architecture of the myelin sheath. Glial cells that myelinate axons were found to have a dual role by also supporting the long-term integrity of ..

A role for humoral mechanisms in the pathogenesis of Devic's neuromyelitis optica

..Based on this study, future therapeutic strategies designed to limit the deleterious effects of complement activation, eosinophil degranulation and neutrophil/macrophage/microglial activation are worthy of further investigation...

The mystery and magic of glia: a perspective on their roles in health and disease

Ben A BarresDepartment of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USANeuron 60:430-40. 2008

..I argue that until the roles of nonneuronal cells are more fully understood and considered, neurobiology as a whole will progress only slowly...

Julia J HarrisDepartment of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United KingdomJ Neurosci 32:356-71. 2012

..Finally, we show that mitochondria in optic nerve axons could sustain measured firing rates with a plausible density of glucose transporters in the nodal membrane, without the need for energy transfer from oligodendrocytes...

Kristjan R JessenDepartment of Cell and Developmental Biology, University College London, London, United KingdomGlia 56:1552-65. 2008

..In neuropathies, however, activation of these pathways is likely to be harmful because they may be key contributors to demyelination, a situation which would open new routes for clinical intervention...

..Here we review current work on the mechanisms of WD with an emphasis on deciphering this mystery and on understanding whether slow WD in the CNS could account for the failure of CNS axons to regenerate...

..Our results support the concept that prompt remyelination protects axons from demyelination-associated axonal loss and that remyelination failure contributes to the axon loss that occurs in multiple sclerosis...

..nervous systems in vertebrates has been accompanied by, and probably dependent on, the acquisition of the myelin sheath. Although there has been substantial progress in our understanding of the factors that determine glial cell ..

..Studies have also demonstrated an unexpected level of plasticity of myelin in the adult CNS. These recent advances provide new insight into how remyelination may be stimulated in demyelinating disorders such as multiple sclerosis...

The myelin sheath wraps large axons in both the CNS and the PNS, and is a key determinant of efficient axonal function and health. Myelin is targeted in a series of diseases, notably multiple sclerosis (MS)...

..Together, these findings show that miR-219 plays a critical role in coupling differentiation to proliferation arrest in the OL lineage, enabling the rapid transition from proliferating OPCs to myelinating OLs...

..myelination is more severely delayed than when manipulating N-cadherin alone, but without any defect to the myelin sheath. Together, our results suggest that N-cadherin interacts with β-catenin in establishing SC polarity and the ..

Sox10 is required for Schwann-cell homeostasis and myelin maintenance in the adult peripheral nerve

..Our results indicate that RXR-γ is a positive regulator of endogenous oligodendrocyte precursor cell differentiation and remyelination and might be a pharmacological target for regenerative therapy in the CNS...

Differentiation block of oligodendroglial progenitor cells as a cause for remyelination failure in chronic multiple sclerosis

..A strong correlation between MWF and the optical density from the luxol fast blue histological stain for myelin was observed in formalin-fixed brain, supporting the use of the MWF as an in vivo myelin marker...

Myelin water imaging of multiple sclerosis at 7 T: correlations with histopathology

Cornelia LauleDepartment of Radiology, University of British Columbia, Vancouver, BC, CanadaNeuroimage 40:1575-80. 2008

..7 T imaging will allow detailed assessment of myelin pathology to a degree not possible with lower field strengths...

..These data, together with the ability of frabin to induce Cdc42-mediated cell-shape changes in transfected Schwann cells, suggest that Rho GTPase signaling is essential for proper myelination of the peripheral nervous system...

Diameter, organization, and length of the myelin sheath are important determinants of the nerve conduction velocity, but the basic molecular mechanisms that control these parameters are only partially understood...

..These observations were reproduced in part by pharmacological inhibition of BACE1. These data suggest BACE1 inhibition as a therapeutic approach to accelerate regeneration and recovery after peripheral nerve damage...

c-Jun is a negative regulator of myelination

David B ParkinsonDepartment of Anatomy and Developmental Biology, University College London, London WC1E 6BT, England, UKJ Cell Biol 181:625-37. 2008

..Negative regulation of myelination is likely to have significant implications for three areas of Schwann cell biology: the molecular analysis of plasticity, demyelinating pathologies, and the response of peripheral nerves to injury...

The 18.5 kDa isoform of myelin basic protein (MBP) is a major component of the myelin sheath in the central nervous system of higher vertebrates, and a member of a larger family of proteins with a multiplicity of forms and post-..

..Our results indicate that CERS2 activity supports different biological functions: maintenance of myelin, stabilization of the cerebellar as well as renal histological architecture, and protection against hepatocarcinomas...

Xin SunW M Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of AmericaPLoS ONE 5:e9380. 2010

..Anatomical growth often correlates with improved behavioral outcomes. Challenges ahead include testing whether some of the most promising treatment strategies in animal models are also beneficial for human patients suffering from SCI...

Interactions between Schwann cells and macrophages in injury and inherited demyelinating disease

..Knowledge of the molecular mechanisms underlying Schwann cell-macrophage interaction under pathological conditions is an important prerequisite to develop effective treatment strategies for various peripheral nerve disorders...

A dual role of erbB2 in myelination and in expansion of the schwann cell precursor pool

..Our results provide strong evidence that TLR signaling plays a critical role in orchestrating the innate immune response leading to efficient and rapid clearance of inhibitory myelin debris and nerve regeneration...

Research Grants64

..likely display enhanced sensitivity to such disruptions because of their primary role in the generation of the myelin sheath. The studies described in the current proposal are designed to further characterize this potentially important ..

..sclerosis (MS) is the long-term survival and integrity of neurons and oligodendrocytes, and maintenance of the myelin sheath. Over time, the progressive nature of MS results in a chronic disease course with permanent axonal damage, ..

..have observed using the Surface Forces Apparatus (SFA), which appear to be related to the delamination of the myelin sheath. We hypothesize that the interactions between the cytoplasmic sides of the membranes are due primarily to ..

..have already shown promising clinical and pre- clinical results with tolerization to these components of the myelin sheath. Both tolerization to proteins and to lipids ameliorates paralysis in EAE...

..uncovered a previously unrecognized function of FGFR1/2 signaling in OLs that contributes to the regulation of myelin sheath thickness and suggests that initial ensheathment of axons and subsequent myelin growth is likely to be ..

..by the progressive disruption and breakdown with partial or attempted re-formation of the highly ordered myelin sheath. The ability to accurately measure these extremely subtle features of myelin, enabled by the new NOVA ..

..2) Correlate the functional consequences of demyelination with structural changes in the myelin sheath. 3) Use the hybrid system chip to monitor functional recovery associated with remyelination in vitro...

..identified, a detailed understanding of the basic mechanisms underlying communication between the axon and the myelin sheath is essential to the future development of novel therapeutic regimens for Multiple Sclerosis...

..the cause of disease has recently been identified: the patients lack a type of fatty acids that make up myelin sheath. The goal of this project is to develop therapeutics to provide the missing fatty acids to patients'..

..Multiple sclerosis (MS) is a devastating disease of the central nervous system characterized by loss of the myelin sheath surrounding nerve processes, leading to impaired conduction and permanent disability...

..Moreover, we will determine if the continued expression of this protein is required for the maintenance of the myelin sheath, and we will also assess if this protein has a similar essential function in the remyelination process...

DESCRIPTION (provided by applicant): Wrapping of the myelin sheath around axons by oligodendrocytes (OLs) is critical for the rapid conduction of electrical signals that are required for normal functioning of the CNS...

..1G and its association with spectrin and the actin cytoskeleton, thereby promoting long-term viability of the myelin sheath. Understanding the functional role of the Necl-4 complex could yield new insight into the molecular mechanisms ..

..Moreover, these axons were characterized by having a disproportionately thinner myelin sheath. Based on these observations, this proposal is based on the central hypothesis that perinatal exposure to ..

The myelin sheath forms by the spiral wrapping of a glial membrane around an axon. The;mechanisms responsible for this process are unknown but are likely to involve changes in the glial cell cytoskeleton...

..inflammation, invasion of the nervous tissue by cells of the immune system, and specific attack on the myelin sheath. It is not clear what the initial lesion is, how cells are attracted to the myelin, or how they cross the ..

Ultimately, we want to understand how the myelin sheath acquires its extraordinary morphology, and so provide the groundwork for understanding a wide variety of de- and dysmyelinating disease states, such as Multiple Sclerosis, Guillain-..

..that mutations cause CMTX, that Cx32 is localized to incisures and paranodes (regions of the Schwann cell (SC) myelin sheath that are composed on non-compact myelin) and that the SC myelin sheath contains functional gap junctions...

..4 million people in the US and more than 2 million worldwide. Memory T cells specific for components of the myelin sheath appear to be crucial for the pathogenesis of MS. With the voltage-gated potassium channel Kv1...

..that are thought to affect its ability to mediate the radial diffusion of substances through the Schwann cell myelin sheath. CMTX is genetically as well as phenotypically heterogeneous: over 200 different defects in the coding region ..

..play a role in the expression of the activity of UDP-galactose:ceramide galactosyltransferase, and 3) the rat myelin sheath, as well as isolated axolemma-enriched fractions, contains UDP-galactose:ceramide galactosyltransferase...

..stage, when myelinating Schwann cells have ensheathed axons in a 1:1 manner but have not yet elaborated a myelin sheath. In SCIP-null mice, Schwann cells are transiently arrested at this stage, whereas in Krox-20-null mice, ..

..process suggest that anisotropy is a consequence of diffusion barriers posed by the axon surface membrane and myelin sheath and that the diameter of the axons is an important parameter in determining white matter (WM) ADC...